Error code 004 is comms issue between the User Interface (UI) and the Charge Controller (CC)
If the error occurs within 2 mins of the heater being powered on, it is a comms issue between the UI and the CC
If the installer or electrician is looking at the heater, they can check that the cable between the UI & CC is plugged in correctly. If it is plugged in correctly and there is still a fault, an engineer will need to investigate.
If heater is in warranty, please raise a visit.
Take Part QMKIT2.
DO NOT SEND JUST THE CHARGE CONTROLLER OR UI AS REQUIRES COMPLETE QMKIT2
If the error occurs after 2 mins or it randomly happens after some time, this suggests a software issue. Most engineers will not have the special software tool so part QMKIT2 should be requested as it is pre-programmed.
In guarantee please submit a ticket.
If out of warranty, contact nearest service agent to attend see additional help link for list of service agents below.
Require additional help? Please follow link below